Items of electronic equipment are usually provided with access in the form of a hatch or a cover that can be removed so as to be able to work on the boards and/or circuits of the item of equipment, notably during a repair or an inspection. Nevertheless, the opening of such a hatch is usually reserved for very particular situations and must not be able to be carried out inappropriately or by an unauthorized person. Therefore, known devices make it possible to detect the inopportune opening of a hatch and then to raise an alarm or to neutralize the item of equipment when such an opening occurs. Conventionally, two techniques are adopted.
A first technique consists in the use of an electromechanical switch attached to an electronic circuit board situated inside the item of equipment. A nipple secured to the hatch pushes the switch down when the hatch is put in place, and then the switch is released with the removal of the hatch. This solution is well suited to the detection of opening of a hatch parallel to the plane of the electronic circuit boards. However, when the plane of the hatch is orthogonal to the planes of the electronic circuit boards contained in the item of equipment, it is necessary to employ a switch with large dimensions, impossible to house in a small space.
According to a second known technique, conductive spaces are reserved on an electronic circuit board and the hatch comprises an element that short-circuits these two spaces when it is put in place. This second technique is applicable when the electronic circuit boards are parallel to the hatch but is not suitable for a configuration in which the hatch is orthogonal to the boards.